Seen hooks like that when I was a kid when we lived in Fiji. The similarity is in the shank/eye, the hooks that I saw were being used for grouper and tuna, and they were more like 3" long or so from what I remember (from over 30 years ago).
Those do look like a stout salmon hook, should not have to worry about an eye unfolding (opening up). Probably a fairly expensive hook to manufacture.